Aerobic exercise greatly increases hippocampas volume in older women
The hippocampus is a small region of the brain that forms part of the limbic system and is primarily associated with memory and spatial navigation. The hippocampus has become a focus of interest in dementia research because it is the area of the brain involved in verbal memory and learning, but it is very sensitive to the effects of aging and neurological damage.
In this new study researchers from Canada, examined the effect of resistance training and aerobic exercise on hippocampal volume and the association between change in hippocampal volume and change in memory.
The study included 86 women, aged 70 to 80 years old with probable cognitive impairment and living independently at home.
Participants at random were assigned to a twice weekly hour long sessions of aerobic training (brisk walking), resistance training, such as lunges, squats, and weights; or balance and muscle toning exercises, for a period of six months.
At the beginning and end of study the size of the hippocampus was assessed by using a 3T MRI scan (gold standard in neuroimaging) to determine hippocampal volume. Verbal memory and learning were assessed by Rey's Auditory Verbal Learning Test.
Only 29 of the women had before and after MRI scans, but the results showed that the total volume of the hippocampus in the group who had completed the full six months of aerobic training was significantly larger than that of those who had lasted the course doing balance and muscle toning exercises.
No such difference in hippocampal volume was seen in those doing resistance training compared with the balance and muscle toning group.
Aerobic training significantly improved left, right and total hippocampal volumes. After accounting for baseline cognitive function and experimental group, increased left hippocampal volume was independently associated with reduced verbal memory and learning performance as indexed by loss after interference.
In their conclusion the researchers write “Aerobic training significantly increased hippocampal volume in older women with probable MCI.”” More research is needed to ascertain the relevance of exercise-induced changes in hippocampal volume on memory performance in older adults with MCI.”
At the very least, aerobic exercise seems to be able to slow the shrinkage of the hippocampus and maintain the volume in a group of women who are at risk of developing dementia, said the researchers.
They recommend regular aerobic exercise to stave off mild cognitive decline, which is especially important, given the mounting evidence showing that regular exercise is good for cognitive function and overall brain health, and the rising toll of dementia.
According to the World Health Organization;
Worldwide, 35.6 million people have dementia, with just over half (58%) living in low- and middle-income countries. Every year, there are 7.7 million new cases.
The estimated proportion of the general population aged 60 and over with dementia at a given time is between 2 to 8 per 100 people.
The total number of people with dementia is projected to almost double every 20 years, to 65.7 million in 2030 and 115.4 million in 2050. Much of this increase is attributable to the rising numbers of people with dementia living in low- and middle-income countries.
This study is published online in the British Journal of Sports Medicine.